1. Field of the Invention
The present invention relates to a closed loop method and apparatus for processing materials, preferably metals such as aluminum, in an environmentally safe closed loop process for surface treating the material with the preferred process being the alodine processing of aluminum.
2. Description of the Prior Art
The assignee of the present invention has been alodine processing large aluminum assembly such as aluminum bodies or hulls of military vehicles for a number of years. The bodies have been as large as about 26 feet long, 11 feet wide and 7 feet high. However, this prior art process was slow, taking about 50 to 80 minutes to complete one body, was wasteful of chemicals used during the process due to cross contamination of chemicals resulting in processing cost of about ten times that of the processing cost of the present invention and required considerable expensive materials and equipment to purify rinse water and other liquids used in the process so that the resulting liquid is environmentally safe to be discharged into city sewers or the like.